Note: On American vines, these reddish/brown lumps are on the leaves. The eggs hatch into aphids; some turn into crawlers and creep down to find roots. Crawlers inject their saliva into roots causing root galls.

How does phylloxera spread?

Spread below ground from root to root and from vine to vine by crawlers.

Fertile adults emerge from the soil and crawl across the ground.

In warm climates, a winged form exists which can fly about 100m.

The female offspring of the winged form of Phylloxera lays winter eggs. What can it hatch into?

Fundatrix; the mother ("queen bee") of a new generation in a new location.

When and where did Thomas Jefferson try to establish vinifera vineyards?

In 1773 he hired Italian grower Filippo Mazzei to establish a 400 acre vineyard adjoining Monticello in Virginia. However, it succumbed to Phylloxera or Oidium (Powerdery Mildew).